WHEN

LARRY BIRKHEAD

threw his arms in the air after being named the father of

Anna Nicole Smith

's baby, who knew he was leading everyone in the chorus of "Y.M.C.A."

According to a "World Exclusive" in the National Enquirer, Birkhead leads a secret gay life. Model Kerrick Ross says he and Birkhead were lovers a half-dozen years ago.

Maybe Anna Nicole's bio should be called "Scared Straight."

"America doesn't know the whole story about Larry Birkhead," Kerrick told the Enquirer.

"He apparently had sex with Anna Nicole and fathered her baby, but there is no question: He also had sex with me!"

(As long as it wasn't at the same time . . . )

Kerrick says the two met at a party in Louisville mid-2000. Larry was selling real estate.

"We were together for about two months and had sex eight to 10 times, always at my apartment. He often spent the whole night with me.

"I had been 'out' for a long time, but Larry was not out of the closet - and he was terrified about his family, who were devout Southern Baptists, finding out he was having a gay relationship," Kerrick says.

Larry's lawyers deny the story.

The Enquirer says Kerrick passed a polygraph test.

* In a possibly related story, the

Associated Press reports Birkhead has only kind words to say about his former paternity suit adversary, Howard K. Stern.

Really? How kind?

"It seems unlikely, but [Stern has] been a great help," Birkhead tells OK! magazine in tomorrow's cover story (for which he was paid). "He's been with Dannielynn the last several months. He knows her likes and dislikes and things that could help me. He gives me credit when I'm doing good things and gives me tips on things I should do a little different."

As for Dannielynn's health, "The doctors say she's fine and has met all of her developmental milestones," Birkhead says. "She's a really curious, alert baby."

One can only imagine how curious a baby she will be.

* Meanwhile, TMZ.com says

Larry is fighting back against tabloids painting him as "a deadbeat, IRS-defrauding, shoplifting, child-abandoning, secretly gay man who parties 'til the wee hours of the morning with beautiful women, impregnating some of them."

How does he find the energy?

TMZ.com says Birkhead has hired noted celebrity attorney Marty Singer to sue some of the tabs for defamation.

Reportedly, Birkhead believes he's become a tabloid target because he sold the first pictures of him and Dannielynn to OK!. He is said to be putting that money into a trust for his daughter, who will not need it if she collects that $435 million mom was after.

Mean girl, or just careless?

Remember when Lindsay Lohan and Hard Rock heir Harry Morton were one of Hollywood's hot, young couples?

Their relationship, alas, ended in a little puddle of sorrow.

Last month, Lindsay turned Harry's condo into a big puddle.

According to an incident report from Sierra Towers obtained by TMZ.com, Lindsay reportedly left the water running in her bathtub, and the flood caused more than $150,000 in damage to Harry's apartment below hers.

And we thought post-split elevator meetings would be awkward.

Lindsay's rep told TMZ.com that Lindsay was in New York on the night in question, but TMZ has video of Lindsay at an L.A. club on the night of the flood.

* Life & Style Weekly reports

that Lindsay will not be teaming with Keira Knightley for "The Best Time of Our Lives."

Her peeps were supposedly

unable to agree on terms with the film's producers.

What, we ask, was everyone waiting for? An anonymous insider says the movie was supposed to start shooting this Saturday.

* Another film Lindsay won't be

making is the Stevie Nicks story.

The Fleetwood Mac chanteuse tells Blender: "Lindsay Lohan thinks she is going to play me! But what the hell movie does she think she's talking about? There is no book, there is no screenplay, there is no movie.

"There is never going to be a movie made without me, because it's never going to be the story of me. Even though a lot has been written about me, the fact is that nobody actually has a clue to what my life was really like. So good luck, Lindsay."

Film Fest winners

They gave out the awards last night at the 16th annual Phila-

delphia Film Festival:

Archie Award (in memory of Archie Perlmutter) for Best First-Time Director: Andrea Arnold, director of "Red Road."

* Jury Awards:

Best Feature: "Tazza: The High-Rollers" (director Chi Dong-hoon). Best Documentary: "The Cats of Mirikitani" (dir. Linda Hattendorf). Best Debut: "Broken English" (dir. Zoe Cassavetes). Best Director: Sean Fine & Andrea Nix Fine for "War/Dance." Best American Independent: "Rocket Science" (director Jeffrey Blitz).

* Audience Awards:

Best Documentary: "Judy Toll: The Funniest Woman

You've Never Heard Of" (director Gary Toll). Danger After Dark: "Severance" (director Christopher Smith). Best Feature Film: "La Vie En Rose" (director Olivier Dahan). *

Daily News wire services contributed to this report.